Since the earliest cars are now approaching 4+ years old and mileage is building up, I'm wondering if anyone has had to replace their EDC dampers yet. Are there any aftermarket options or at that point do you just replace the whole assembly with coilovers? Looking at prices for EDC components, it looks like its going to be a very expensive maintenance item.

11k miles and my front struts needed to be replaced. Granted there was a lot of construction going on around my work and roads were horrible, but still, would think a car of this caliber should be able to handle rough roads and it's not like I was speeding on them. W/O warranty would have been around a $3k job (each strut retails at $1,300), but luckily warranty took care of it.

Nope, not a warranty item unless you have an early failure (like mhabs). As was mentioned above, dampers are a wear and tear item. The only time they would be covered is under a maintenance plan but BMW doesn't include dampers in any of their maintenance plans to my knowledge.